Edge effects of roads on temperature, light, canopy cover, and canopy height in laurel and pine forests (Tenerife, Canary Islands)

The estimation of the road edge effect is useful to understand changes induced by the road network on ecosystems. Road networks on islands may break ecosystem integrity through microclimate edge effects, which are known to be associated with disturbances to animal and plant communities. Road edge effects have been scarcely studied on oceanic islands. In this paper we studied road edge effects on microclimate and canopy structure in laurel and pine forests in Tenerife (Canary Islands). We assessed depth of road edge effect for temperature at four vertical layers (soil, litter and air at 5 cm and 1.3 m above ground), light intensity, canopy cover and height, in transects running from narrow (6–7 m width) asphalt roads and dust trails to 100 m to the interior of both forests. We used an ANOVA procedure with Helmert difference contrasts to identify the distances along transects over which edge effects were significant. We detected significant gradients for most parameters but they were consistently narrow both within and between forests. In the laurel forest, we detected highly significant gradients for soil temperature, light, and canopy cover and height in both asphalt and unpaved roads. In the pine forest, we detected a highly significant gradient for soil temperature at asphalt roads, and a significant light gradient for both asphalt and unpaved roads. From the road edge to the forest interior, significant temperature changes persisted for only 3 m, light variation persisted for 6 m, and canopy cover and height changed significantly within the first 10 m. Asphalt roads and dust trails revealed different patterns of variation for temperature between edge and interior. No differences were found between the two types of roads in edge-interior trends for light or canopy structure. The abruptness of microclimate and canopy gradients was slightly higher in the laurel forest than in the pine forest, caused by a higher edge contrast in the former. The depth of the road edge effect found in laurel and pine forests was small, but it could have cumulative effects on forest microclimate and forest associated biota at the island scale. Such changes deserve attention by local road managers for planning and design purposes.     

Anthropogenic acidification effects in primeval forests in the Transcarpathian Mts., western Ukraine

The precipitation chemistry, deposition, nutrient pools and composition of soils and soil water, as well as an estimate of historical deposition of sulphur (S) and inorganic nitrogen (N) for the period 1860-2008, were determined in primeval deciduous and coniferous forests at the sites Javornik and Pop Ivan, respectively. Measured S throughfall inputs of 10 kg ha^− 1 year^− 1 in 2008 were similar to those estimated for the period 1900-1950 at both sites. The highest estimated S inputs were in the 1980s. Measured bulk deposition of N in 2008 was lower at Pop Ivan (5.6 kg ha^− 1 year^− 1) compared to Javornik (12 kg ha^− 1 year^− 1). Significantly lower NO₃ deposition was both estimated and measured at Pop Ivan. Higher soil base cation concentrations were observed at well-buffered Javornik underlain by flysch (Ca pool of 2046 kg ha^− 1 and base saturation of 29%) compared to Pop Ivan underlain by crystalline schist (Ca pool of 186 kg ha^− 1 and base saturation of 6.5%). The soil pool of organic carbon (C) was higher at Pop Ivan (212 t ha^− 1) compared to Javornik (127 t ha^− 1). The C concentration was positively correlated with organic N in the soil (p < 0.001) at both sites, but the mass average C/N ratio in the forest floor was lower at Javornik (22) than at Pop Ivan (26). High N leaching of 17 kg ha^− 1 year^− 1 at the 90 cm depth was measured in the soil water at Javornik, suggesting high mineralization and nitrification rates in old growth deciduous forests in the area. Despite relatively low Al concentrations in the soil water, a low soil water Bc/Al ratio (0.9) (Bc = Ca + Mg + K) was found in the upper mineral soil at Pop Ivan. This suggests that the spruce forest ecosystems in the area are vulnerable to anthropogenic acidification and to the adverse effects of Al on forest root systems.     

The effects of phytophagous insects on water and soil nutrient concentrations and fluxes through forest stands of the Level II monitoring network in the UK

The effects of insect defoliators on throughfall and soil nutrient fluxes were studied in coniferous and deciduous stands at five UK intensive monitoring plots (1998 to 2008). Links were found between the dissolved organic carbon (DOC), nitrogen (N) and potassium (K) fluxes through the forest system to biological activity within the canopy. Underlying soil type determined the leaching or accumulation of these elements. Under oak, monitored at two sites, frass from caterpillars of Tortrix viridana and Operophtera brumata added direct deposition of ~ 16 kg ha⁻¹extra N during defoliation. Peaks of nitrate (NO₃-N) flux between 5 and 9 kg ha⁻¹ (×5 usual winter values) were recorded in consecutive years in shallow soil waters. Synchronous rises in deep soil NO₃-N fluxes at the Grizedale sandy site indicate downward flushing, not seen at the clay site. Under three Sitka spruce stands, generation of honeydew (DOC) was attributed to two aphid species (Elatobium abietinum and Cinara pilicornis) with distinctive feeding strategies. Throughfall DOC showed mean annual fluxes (6 seasons) ~ 45-60 kg ha⁻¹ compared with rainfall values of 14-22 kg ha⁻¹. Increases of total N in throughfall and NO₃-N fluxes in shallow soil solution were detected — soil water fluxes reached  8 kg ha⁻¹ in Llyn Brianne, ~ 25 kg ha⁻¹ in Tummel, and ~ 40 kg NO₃-N ha⁻¹ in Coalburn. At Tummel, on sandy soil, NO₃-N leaching showed increased concentration at depth, attributed to microbiological activity within the soil. By contrast, at Coalburn and Llyn Brianne, sites on peaty gleys, soil water NO₃-N was retained mostly within the humus layer. Soil type is thus key to predicting N movement and retention patterns. These long term analyses show important direct and indirect effects of phytophagous insects in forest ecosystems, on above and below ground processes affecting tree growth, soil condition, vegetation and water quality.     

Emission of CO2 and N2O from soil cultivated with common bean (Phaseolus vulgaris L.) fertilized with different N sources

Addition of different forms of nitrogen fertilizer to cultivated soil is known to affect carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions. In this study, the effect of urea, wastewater sludge and vermicompost on emissions of CO₂ and N₂O in soil cultivated with bean was investigated. Beans were cultivated in the greenhouse in three consecutive experiments, fertilized with or without wastewater sludge at two application rates (33 and 55 Mg fresh wastewater sludge ha^− 1, i.e. 48 and 80 kg N ha^− 1 considering a N mineralization rate of 40%), vermicompost derived from the wastewater sludge (212 Mg ha^− 1, i.e. 80 kg N ha^− 1) or urea (170 kg ha^− 1, i.e. 80 kg N ha^− 1), while pH, electrolytic conductivity (EC), inorganic nitrogen and CO₂ and N₂O emissions were monitored. Vermicompost added to soil increased EC at onset of the experiment, but thereafter values were similar to the other treatments. Most of the NO₃⁻ was taken up by the plants, although some was leached from the upper to the lower soil layer. CO₂ emission was 375 C kg ha^− 1 y^− 1 in the unamended soil, 340 kg C ha^− 1 y^− 1 in the urea-amended soil and 839 kg ha^− 1 y^− 1 in the vermicompost-amended soil. N₂O emission was 2.92 kg N ha^− 1 y^− 1 in soil amended with 55 Mg wastewater sludge ha^− 1, but only 0.03 kg N ha^− 1 y^− 1 in the unamended soil. The emission of CO₂ was affected by the phenological stage of the plant while organic fertilizer increased the CO₂ and N₂O emission, and the yield per plant. Environmental and economic implications must to be considered to decide how many, how often and what kind of organic fertilizer could be used to increase yields, while limiting soil deterioration and greenhouse gas emissions.     

Runoff of pharmaceuticals and personal care products following application of biosolids to an agricultural field

Municipal biosolids are a source of nutrients for crop production. Beneficial Management Practices (BMPs) can be used to minimize the risk of contamination of adjacent water resources with chemical or microbial agents that are of public or environmental health concern. In this field study, we applied biosolids slurry at a commercial rate using either subsurface injection or broadcast application followed by incorporation. Precipitation was simulated at 1, 3, 7, 22, 36 and 266 days post-application on 2 m² microplots to evaluate surface runoff of 9 model pharmaceuticals and personal care products (PPCPs), atenolol, carbamazepine, cotinine, gemfibrozil, naproxen, ibuprofen, acetaminophen, sulfamethoxazole and triclosan. In runoff from the injected plots, concentrations of the model PPCPs were generally below the limits of quantitation. In contrast, in the broadcast application treatment, the concentrations of atenolol, carbamazepine, cotinine, gemfibrozil, naproxen, sulfamethoxazole and triclosan on the day following application ranged from 70-1477 ng L^− 1 in runoff and generally declined thereafter with first order kinetics. The total mass of PPCPs mobilized in surface runoff per m² of the field ranged from 0.63 µg for atenolol to 21.1 µg for ibuprofen. For ibuprofen and acetaminophen, concentrations in runoff first decreased and then increased, suggesting that these drugs were initially chemically or physically sequestered in the biosolids slurry, and subsequently released in the soil. Carbamazepine and triclosan were detected at low concentrations in a runoff event 266 days after broadcast application. Overall, this study showed that injection of biosolids slurry below the soil surface could effectively eliminate surface runoff of PPCPs.     

Mercury contamination in the vicinity of a chlor-alkali plant and potential risks to local population

A mercury-cell chlor-alkali plant operated in Estarreja (North-western Portugal) for 50 years causing widespread environmental contamination. Although production by this process ceased in 2002, mercury contamination from the plant remains significant. The main objective of this study was to investigate mercury impact on the nearby environment and potential risks to local population. To assess the level of contamination soil samples were collected from agricultural fields in the vicinity of the plant, extending the study by taking samples of the predominant vegetation suitable for animal and human consumption, water samples, and fish species from a nearby coastal lagoon, to gain a preliminary insight into the potential for contamination of the terrestrial and aquatic food web. To determine population exposure to mercury, hair samples were collected from local residents. Total mercury concentration in the 0-15 cm layer of soil was found to be highly variable, ranging between 0.010 and 91 mg kg^− 1, although mercury contamination of soils was found to be restricted to a confined area. Lolium perenne roots contained between 0.0070 and 2.0 mg kg^− 1, and there is evidence that root systems uptake mercury from the soil. Levels of mercury in the aerial parts of plants ranged between 0.018 and 0.98 mg kg^− 1. It appears that plants with higher mercury concentration in soils and roots also display higher mercury concentration in leaves.Total mercury concentration in water samples ranged between 12 and 846 ng L^− 1, all samples presenting concentrations below the maximum level allowable for drinking water defined in the Portuguese law (1.0 μg L^− 1).Mercury levels in fish samples were below the maximum limit defined in the Portuguese law (0.5 mg kg^− 1), ranging from 0.0040 to 0.24 mg kg^− 1. Vegetables collected presented maximum mercury concentration of 0.17 mg kg^− 1. In general, food is not contaminated and should not be responsible for major human exposure to the metal.Mercury determined in human hair samples (0.090-4.2 mg kg^− 1; mean 1.5 mg kg^− 1) can be considered within normal limits, according to WHO guidelines suggesting that it is not affecting the local population. Despite being subject to decades of mercury emissions, nowadays this pollutant is only found in limited small areas and must not constitute a risk for human health, should these areas be restricted and monitored.Considering the present data, it appears that the population from Estarreja is currently not being affected by mercury levels that still remain in the environment.     

The effects of low levels of nitrogen deposition and grazing on dune grassland

Coastal sand dunes are considered to be threatened by the atmospheric deposition of nitrogen (N); however, experimental investigations of the effects of N deposition on dune vegetation and soil using realistic N loads and sites with low background deposition are scarce. This study reports the effects of low levels of fertilisation with N and phosphorus (P) on the vegetation, above-ground biomass, plant tissue chemistry and soil chemistry of fixed dune grasslands. In addition, the impacts of grazing management and its potential to mitigate adverse effects of N fertilisation were examined. Four N treatments (unwatered control, watered control, + 7.5 kg ha^− 1 year^− 1, + 15 kg ha^− 1 year^− 1) were combined with three grazing treatments (ungrazed, rabbit grazed, rabbit and pony grazed). In a separate experiment, effects of fertilisation with both N (15 kg ha^− 1 year^− 1) and P (20 kg ha^− 1 year^− 1) were investigated. Vegetation composition was assessed using the point quadrat method. Above-ground biomass, sward heights, tissue N and P concentrations and soil chemical parameters were also measured. After two years, N addition resulted in greater amounts of total above-ground biomass, bryophyte biomass and changes in bryophyte tissue chemistry. No effects on vegetation composition, sward height or soil parameters occurred. Fertilisation with both nutrients had a greater impact on above-ground biomass, sward heights and sward structure than N addition alone. The grazing treatments differed in their species composition. The changes observed after only two years of fertilisation may lead to community changes over longer time scales. Effects were observed even under heavy grazing with phosphorus limitation. Therefore, the upper critical load for N for dune grasslands may be below the previously proposed 20 kg ha^− 1 year^− 1 and grazing may not mitigate all negative effects of N deposition.     

Daily intake of manganese by local population around Kylleng Pyndengsohiong Mawthabah (Domiasiat), Meghalaya in India

Present work is carried out adjacent to world's highest rainfall area Kylleng Pyndengsohiong (KP) Mawthabah (Domiasiat), Meghalaya in India to establish the baseline value of manganese intake through dietary route by the local tribe population in view of proposed uranium mining. The locally available food items collected from villages surrounding the proposed uranium mining site at KP Mawthabah (Domiasiat) were analysed using Energy Dispersive X-Ray Fluorescence (EDXRF) Technique. The manganese concentration in different food categories varies from 2.76-12.50 mg kg^− 1 in cereals, 1.8-4.20 mg kg^− 1 in leafy vegetables, 0.30-13.50 mg kg^− 1 in non leafy vegetables, 0.50-15.30 mg kg^− 1 in roots and tubers, 0.70-1.50 mg kg^− 1 in fruits and 0.12-0.96 mg kg^− 1 in flesh food. The mean dietary intake of Mn was found to be 3.83 ± 0.25 mg d^− 1 compared to Recommended Dietary Allowances (RDAs) of 2-5 mg d^− 1. The daily intake of Manganese by the local tribe population is comparable with the value (3.7 mg d^− 1) recommended by International Commission on Radiological Protection (ICRP) for reference man and lower than the intake value observed for Indian and other Asian population.     

Responses of streams in central Appalachian Mountain region to reduced acidic deposition—Comparisons with other regions in North America and Europe

Data from 5 wet deposition stations and 21 streams during 1980-2006 were analyzed to investigate chemical responses of streams to reduced acidic deposition in the central Appalachian Mountain region of West Virginia, USA. Wet deposition of acidic anions (i.e., sulfate, nitrate, and chloride) and hydrogen ions decreased significantly during the studied time period. Stream sulfate showed a delayed response to the reduced acidic deposition, and showed a decrease in the 2000s (− 5.54 µeq L^− 1 yr^− 1) and the whole period (− 0.49 µeq L^− 1 yr^− 1). No significant trend of stream nitrate + nitrite and chloride was observed. Stream alkalinity increased in the 1990s (+ 23.33 µeq L^− 1 yr^− 1) and the whole period (+ 7.26 µeq L^− 1 yr^− 1). Stream hydrogen ions decreased in the 1990s (− 0.002 µeq L^− 1 yr^− 1), 2000s (− 0.001 µeq L^− 1 yr^− 1), and the whole period (− 0.001 µeq L^− 1 yr^− 1). Compared with most acidic streams and lakes in the United States and Europe, a lower decreasing rate of hydrogen ions and higher increasing rate of alkalinity were observed in the alkaline West Virginian streams in the 1990s. However, due to their initial negative or zero alkalinity values, those acidic streams showed a higher percent increase in alkalinity than that in the alkaline West Virginian streams (from 800 µeq L^− 1 yr^− 1 to 1200 µeq L^− 1 yr^− 1). Total aluminum in the West Virginian streams decreased in the 1990s (− 0.67 µmol L^− 1 yr^− 1) and the whole period (− 0.22 µmol L^− 1 yr^− 1). The current study advanced our understanding of streams' responses to the reduced acidic deposition in the Mid-Appalachians since the passage of the 1970 and 1990 Amendments to the United States Clean Air Act (US CAAA).     

Evaluation of geosynthetic reinforcement in unpaved road using moving wheel load test

The common cause of failure of the unpaved road is associated with undesirable ruts and deformations. Use of geosynthetic reinforcement is a solution to this pavement distress problem as experienced in limited research works, especially in the laboratory studies. This study presents the performance of geosynthetic-reinforced unpaved roads subjected to moving wheel load tests to investigate the effect of geosynthetic reinforcement on the pavement surface deformation of the unpaved roads. Unreinforced and geosynthetic-reinforced unpaved road test sections consisting of varied reinforcements were constructed in a test pit, 9 m long and 2.7 m wide. Geogrid and geotextile were used for reinforcing the unpaved road test sections. The rut depth was measured in the transverse direction of the wheel path after certain number of wheel passes. Traffic Benefit Ratio (TBR) and Performance Index (PI) were employed in the study for the evaluation of the effectiveness of geosynthetic reinforcement in unpaved roads. After 350 vehicle passes, the geotextile-reinforced and geogrid-reinforced test sections get rutting reduced by 44.89% and 28.57%, respectively. The test results indicate that inclusion of geosynthetic reinforcement significantly improves the rutting resistance and stability of reinforced test sections compared to the unreinforced test sections.     

Impact of selected agricultural management options on the reduction of nitrogen loads in three representative meso scale catchments in Central Germany

Nitrogen inputs into surface waters from diffuse sources are still unduly high and the assessment of mitigation measures is associated with large uncertainties. The objective of this paper is to investigate selected agricultural management scenarios on nitrogen loads and to assess the impact of differing catchment characteristics in central Germany. A new modelling approach, which simulates spatially distributed N-transport and transformation processes in soil and groundwater, was applied to three meso scale catchments with strongly deviating climate, soil and topography conditions. The approach uses the integrated modelling framework JAMS to link an agro-ecosystem, a rainfall-runoff and a groundwater nitrogen transport model. Different agricultural management measures with deviating levels of acceptance were analysed in the three study catchments.N-leaching rates in all three catchments varied with soil type, the lowest leaching rates being obtained for loess soil catchment (18.5 kg nitrate N ha^− 1 yr^− 1) and the highest for the sandy soils catchment (41.2 kg nitrate N ha^− 1 yr^− 1). The simulated baseflow nitrogen concentrations varied between the catchments from 1 to 6 mg N l^− 1, reflecting the nitrogen reduction capacity of the subsurfaces. The management scenarios showed that the highest N leaching reduction could be achieved by good site-adapted agricultural management options. Nitrogen retention in the subsurface did not alter the ranking of the management scenarios calculated as losses from the soil zone. The reduction effect depended strongly on site specific conditions, especially climate, soil variety and the regional formation of the crop rotations.     

Evaluation of the EUROSEM model for predicting the effects of erosion-control blankets on runoff and interrill soil erosion by water

The European Soil Erosion Model (EUROSEM, Morgan et al., 1998) is an event-based soil erosion model which predicts runoff and sediment discharge for different environmental conditions. Applying geotextiles or erosion-control blankets (ECB’s) on the soil surface significantly affects surface seal formation and topsoil properties and therefore controls runoff and soil erosion rates during a rainfall event. Since these within-storm changes of soil surface characteristics and hydrological conditions are not incorporated in EUROSEM, errors in runoff and soil erosion predictions may occur for soil surfaces covered with ECB’s.Therefore, the objective of this paper is to evaluate and improve the performance of a research version of the physically-based erosion model EUROSEM (EUROSEM-2010; Borselli and Torri, 2010) for simulating the effects of ECB’s on runoff and interrill soil erosion by water during intense simulated rainfall events. Results of model simulations are compared with experimental results of interrill erosion using biological (i.e. natural) ECB’s and simulated rainfall. Because ECB’s applied on the soil surface retard seal formation, the differences between observed and predicted runoff rates and sediment discharges are rather high during the first 20-30 min of the simulated rainstorm. Therefore, a simple approach is proposed to cope with the dynamic evolution of some soil characteristics, i.e. saturated hydraulic conductivity, soil erodibility and soil cohesion, during an intense rainfall event. This time-dependent approach improves the predictions of runoff rate and sediment discharge during the first 20-30 min of a rainfall event and increases the model efficiency (i.e. a measure for the goodness of fit) from 0.84 to 0.98 and from 0.48 to 0.68 for the total runoff volume and soil loss, respectively. For most conditions, the predicted final sediment discharge is still considerably larger than the observed values, which can be partly attributed to the deposition of sediment in the bare soil patches (i.e. inter-weave open areas) of the ECB’s, which is not simulated by EUROSEM in this study. This model approach increases our understanding of the effects of ECB’s on within-storm changes in hydrological conditions and soil surface characteristics.     

Increasing arsenic concentrations in runoff from 12 small forested catchments (Czech Republic, Central Europe): Patterns and controls

The 40-year long period of heavy industrialization in Central Europe (1950-1990) was accompanied by burning of arsenic-rich lignite in thermal power plants, and accumulation of anthropogenic arsenic in forest soils. There are fears that retreating acidification may lead to arsenic mobilization into drinking water, caused by competitive ligand exchange. We present monthly arsenic concentrations in surface runoff from 12 headwater catchments in the Czech Republic for a period of 13 years (1996-2008). The studied area was characterized by a north-south gradient of decreasing pollution. Acidification, caused mainly by SO_x and NO_x emissions from power plants, has been retreating since 1987. Between 1996 and 2003, maximum arsenic concentrations in runoff did not change, and were < 1 ppb in the rural south and < 2 ppb in the industrial north. During the subsequent two years, 2004-2005, maximum arsenic concentrations in runoff increased, reaching 60% of the drinking water limit (10 ppb). Starting in 2006, maximum arsenic concentrations returned to lower values at most sites. We discuss three possible causes of the recent arsenic concentration maximum in runoff. We rule out retreating acidification and a pulse of high industrial emission rates as possible controls. The pH of runoff has not changed since 1996, and is still too low (< 6.5) at most sites for an As-OH⁻ ligand exchange to become significant. Elevated arsenic concentrations in runoff in 2004-2005 may reflect climate change through changing hydrological conditions at some, but not all sites. Dry conditions may result in elevated production of DOC and sulfur oxidation in the soil. Subsequent wet conditions may be accompanied by acidification leading to faster dissolution of arsenic-bearing sulfides, dissolution of arsenic-bearing Fe-oxyhydroxides, and elevated transport of arsenic sorbed on organic matter. Anaerobic domains exist in normally well-aerated upland soils for hours-to-days following precipitation events.     

Comparison of laboratory methodologies for evaluating radiostrontium diffusion in soils: Planar-source versus half-cell methods

A planar-source method, initially designed to obtain diffusion coefficients in compacted clay, is adapted here to determine the apparent diffusion coefficient (D_a) of radiostrontium in soils representative of the Spanish territory. Experiments were carried out by varying the moisture content (F_moist), and bulk dry density (ρ_bulk) of the soil samples, in order to study the influence of these soil packing parameters on D_a values.The moisture in the soil samples was established as the percentage of occupancy of each soil's field capacity (OFC). For a similar OFC, D_a values in the examined soils ranged by approximately one order of magnitude (e.g. from 6.2 × 10⁻¹¹ to 6.5 × 10⁻¹² m² s⁻¹, at 100% of OFC; from 3.0 × 10⁻¹¹ to 3.8 × 10⁻¹² m² s⁻¹, at 60% of OFC). For a given soil, D_a values increased when water content was increased. F_moist, and tortuosity (τ) explained D_a variability, with R² values usually over 0.9. However, no good simple or multiple regressions between the soil packing parameters and D_a were obtained with the whole dataset of all soils, which indicated that soil sorption capacity affects the diffusion of reactive radionuclides in soils. The inclusion of calculated K_d values in the multiple regressions improved the correlations in all cases.Finally, D_a values were compared with those obtained by the application of a half-cell method. The values of D_a obtained by the planar-source methods were systematically lower than the half-cell ones, with a good correlation between the D_a derived from both methods (R² = 0.98).     

Distribution of (210)Pb and (210)Po in boreal forest soil

Vertical distribution and activity contents of ²¹⁰Pb and ²¹⁰Po were investigated in forest soils of Scots pine-dominated (Pinus sylvestris L.) stands from seven different locations in Finland. The mean total inventory in the soil profile, up to 20 cm, of ²¹⁰Pb was 4.0 kBq m^− 2 (range 3.1-5.0 kBq m^− 2) and ²¹⁰Po 5.5 kBq m^− 2 (range 4.0-7.4 kBq m^− 2), the organic soil layer containing 45% of the total inventory of both nuclides. In both the organic and the mineral layers the ²¹⁰Po/²¹⁰Pb ratio was close to unity indicating a radioactive equilibrium between them. In the litter layer there was, however, a clear excess of ²¹⁰Po suggesting that polonium is recycled via root uptake from the root zone to the ground surface. The activity concentration (Bq kg^− 1) of ²¹⁰Pb clearly correlated with organic matter and the Fe, Al and Mn concentrations in soil indicating that radioactive lead is associated both with humic substances and the oxides of iron, aluminium and manganese. Radioactive lead was also seen to follow the behavior of stable lead. No systematic correlation between polonium and soil properties was seen.     

Modelling recovery from soil acidification in European forests under climate change

A simple soil acidification model was applied to evaluate the effects of sulphur and nitrogen emission reductions on the recovery of acidified European forest soils. In addition we included the effects of climate change on soil solution chemistry, by modelling temperature effects on soil chemical processes and including temperature and precipitation effects on nitrogen uptake and on leaching. Model results showed a strong effect of the emission reduction scenarios on soil solution chemistry. Using the Current Legislation (CLE) scenario, the forest area in Europe with soil solution Al/Bc >1 mol mol^− 1 (a widely used critical limit) decreased from about 4% in 1990 to about 1.7% in 2050. Under Maximum Feasible Reductions (MFR), the exceeded area will be < 1% in 2050. In addition, the area where limits for the nitrate concentration in soils are violated is predicted to be smaller under MFR than under CLE. Using the most stringent criterion for nitrate ([NO₃] <0.3 mg l^− 1), the area with nitrate concentrations in excess of the critical limit is about 33% in 2050 under CLE, but only 12% under MFR. Recovery, i.e. attaining non-violation of the criterion, is also much faster under MFR than under CLE. Climate change leads to higher weathering rates and nitrogen uptake in the model, but positive effects on recovery from acidification are limited compared to current climate, and differences between the A1 and B2 climate change scenarios were small. Target loads for 2050 exist for 4% of the area for Al/Bc = 1 and for 12% of the area when using a criterion of ANC = 0 for the soil solution. In about 30% of the area where meaningful target loads exists, the computed target load is lower than the deposition under MFR, and thus cannot be attained with current emission abatement technologies.     

Pharmaceutical and personal care products in tile drainage following surface spreading and injection of dewatered municipal biosolids to an agricultural field

Land application of municipal biosolids can be a source of environmental contamination by pharmaceutical and personal care products (PPCPs). This study examined PPCP concentrations/temporally discrete mass loads in agricultural tile drainage systems where two applications of biosolids had previously taken place. The field plots received liquid municipal biosolids (LMB) in the fall of 2005 at an application rate of ∼ 93,500 L ha^− 1, and a second land application was conducted using dewatered municipal biosolids (DMB) applied at a rate of ∼ 8 Mt dw ha^− 1 in the summer of 2006. The DMB land application treatments consisted of direct injection (DI) of the DMB beneath the soil surface at a nominal depth of ∼ 0.11 m, and surface spreading (SS) plus subsequent tillage incorporation of DMB in the topsoil (∼ 0.10 m depth). The PPCPs examined included eight pharmaceuticals (acetaminophen, fluoxetine, ibuprofen, gemfibrozil, naproxen, carbamazepine, atenolol, sulfamethoxazole), the nicotine metabolite cotinine, and two antibacterial personal care products triclosan and triclocarban. Residues of naproxen, cotinine, atenolol and triclosan originating from the fall 2005 LMB application were detected in tile water nearly nine months after application (triclocarban was not measured in 2005). There were no significant differences (p > 0.05) in PPCP mass loads among the two DMB land application treatments (i.e., SS vs. DI); although, average PPCP mass loads late in the study season (> 100 days after application) were consistently higher for the DI treatment relative to the SS treatment. While the concentration of triclosan (∼ 14,000 ng g^− 1 dw) in DMB was about twice that of triclocarban (∼ 8000 ng g^− 1 dw), the average tile water concentrations for triclosan were much higher (43 ± 5 ng L^− 1) than they were for triclocarban (0.73 ± 0.14 ng L^− 1). Triclosan concentrations (maximum observed in 2006 ∼ 235 ng L^− 1) in tile water resulting from land applications may warrant attention from a toxicological perspective.     

Deforestation and greenhouse gas emissions associated with fuelwood consumption of the brick making industry in Sudan

The study focuses on the role of the fired clay brick making industry (BMI) on deforestation and greenhouse gas (GHG) emissions in Sudan. The BMI is based on numerous kilns that use biomass fuel, mainly wood which is largely harvested unsustainably. This results in potential deforestation and land degradation. Fuelwood consumption data was collected using interviews and questionnaires from 25 BMI enterprises in three administrative regions, namely Khartoum, Kassala and Gezira. Annual fuelwood consumption data (t dm yr^− 1) was converted into harvested biomass (m³) using a wood density value of 0.65 t dm m^− 3. For annual GHG estimations, the methodological approach outlined by the Intergovernmental Panel on Climate Change (IPCC) was used. According to our results, the annual deforestation associated with the BMI for the whole of Sudan is 508.4 × 10³ m³ of wood biomass, including 267.6 × 10³ m³ round wood and 240.8 × 10³ m³ branches and small trees. Total GHG emissions from the Sudanese BMI are estimated at 378 028 t CO₂, 15 554 t CO, 1778 t CH₄, 442 t NO_X, 288 t NO and 12 t N₂O per annum. The combined CO₂-equivalent (global warming potential for 100-year time horizon) of the GHG emissions (excluding NO_X and NO) is 455 666 t yr^− 1. While these emissions form only a small part of Sudan's total GHG emissions, the associated deforestation and land degradation is of concern and effort should be made for greater use of sustainable forest resources and management.     

Catchment condition as a major control on the quality of receiving basin sediments (Sydney Harbour, Australia)

The current work aimed to compile existing information to better understand the source, fate and effects of metallic contaminants in one catchment-receiving basin system (Iron Cove) in Sydney Harbour (Australia). Copper, Pb and Zn concentrations of potential source materials, i.e. soils (mean 62, 410 and 340 µg g^− 1, respectively) and road dust (mean 160, 490 and 520 µg g^− 1, respectively) and in materials being transported to the estuary, i.e. in gully pots (mean 110, 200 and 260 µg g^− 1 for Cu, Pb, and Zn, respectively), in bedload (mean 210, 880 and 1700 µg g^− 1, respectively) and particulates in canals draining the catchment (mean 325, 290 and 1865 µg g^− 1, respectively) were highly enriched. Estuarine sediments in the receiving basin are enriched 20 times over pre-anthropogenic concentrations and are toxic to benthic animals at the canal mouths. Stormwater remediation is required to reduce metal loads to the adjacent estuary.     

Comparison of the ozonation and Fenton process performances for the treatment of antibiotic containing manure

An integrated treatment method based on magnesium salt extraction followed by chemical oxidation was used for the treatment of a veterinary antibiotic, oxytetracycline (OTC) contaminated cow manure since animal manure can be an important source for antibiotic pollution in the environment. Pretreatment with magnesium salt enhanced the efficiencies of subsequent oxidation processes by extracting 63.9% of OTC from the manure thereby making it more favorable for oxidation with the hydroxyl radicals produced by the Fenton and ozone oxidation processes. Both the 24 h Fenton oxidation process with 434 mM H₂O₂ and 43.4 mM Fe²⁺ doses and the 1-h ozonation process with an applied ozone dose of 2.5 mg min^− 1 provided more than 90% OTC removal from the manure slurry. However, the second-order OTC removal rate constant of Fenton process (119 M^− 1s^− 1) was remarkably lower than that obtained with the ozonation process (548 M^− 1s^− 1). The oxidant dose was a significant factor for the efficiency of the Fenton treatment but not for the ozone treatment. The efficiencies of both the Fenton and ozone oxidation processes were not affected by the pH adjustment of the manure slurry.